The Final Word on Fermentation with Sandor Katz

“Biodiversity exists within us. We are all experiencing limited biodiversity. Fermented foods help us restore biodiversity.”

“Sandorkraut” holds a bag of sauerkraut

With touseled hair and a relaxed demeanor, Sandor Katz mesmerized the audience at The Mandarin Oriental, Hong Kong, on 13 January, whilst he talked fermentation with a sprinkling of microbiology. The audience was delighted by an array of fermenting samples prepared by a collaboration of MOHK hotel chefs and LantauMama under the deft guidance of Katz. Our “book of treats” included a sourdough pancake, kefir cream cheese, mead, green beans, sauerkraut and more. LantauMama provided a gorgeously fresh chamomile, chrysanthemum and osmanthus kombucha and a coconut and cinnamon kefir to rinse the palate in between delicious samples. All the while, Katz infiltrated our minds with techniques, flavours and importance of biodiversity within our own bodies. Below is some of Katz’s fermentation wisdom from the workshop.

What is Fermentation Anyway?

Katz’s famous sauerkraut and fermented green beans in the MOHK discovery box

Fermentation is the transformative action of microorganisms. For a biologist, fermentation is a bit more broad and specific. Biologists mean fermentation is production of energy without oxygen, as in an anaerobic process. Fermentation, as a byproduct, produces lactic acid. Some typical examples of the fermentation process include crushing grapes and fermenting them into wine, taking milk and turning it into milk kefir. However, there is a rather large handful of delicious foods that do require oxygen for fermentation such as vinegar, kombucha, blue cheeses, and tempeh. This is why I prefers the broader understanding of fermentation.

Plants and Animals

All plants and animals host communities of microorganisms. Over the course of history, and through some happy accidents, humans have learned to manipulate conditions in a variety of ways that encourage growth of some organisms whilst discouraging growth of others. For example, if we submerge vegetables in liquid and salt, mold cannot grow. The vegetables are protected from the free-flow of oxygen and instead of decomposition, lactic acid bacteria proliferates thereby protecting undesirable and dangerous bacteria from growing.

Why is it in every part of the world?

Humans figured out this process thousands of years ago. Submerge rather than allow decomposition. In a sour environment vegetables are stable and it protects people from getting sick. There is no documentation of food poisoning from fermented foods. Any food can be fermented and digested by microorganisms. Some places have more common traditions. Agriculture would not be possible without fermentation.

Practical Benefits – Preservation!

Alcohol is certainly the most widespread form of fermentation. Any course of carbohydrate can and is turned into alcohol from grains to fruit. The single most practical form of fermentation is for preservation. The other options for preserving food include canning, which is only about 200 years old, and drying foods by .

Perceived Health Benefits of Fermentation

The process of fermentation transforms foods in some clear patterns…

Pre-digestion: This is the simple idea that as food is fermented, nutrients are being digested by the organisms. Take soybeans, for example. They are the most concentrated plant source of protein. Humans can eat young soybeans such as edamame, but not adult edamame because it will give you indigestion. Long before microbiology, people figured out different methods of fermenting soybeans to access the nutrient dense food such as soy sauce, miso, natto, tempeh, and many more. Each product requires different amount of time, organisms, temperatures, etc. Fermentation breaks down the protein into amino acids, which are the building blocks of proteins, transforming them into a more digestible form.

Detoxification: In their natural form oxalic acid, phytic acid (found in grains and beans and binds to minerals) and cyanide (cassava, nuts) are all toxic to humans. Fortunately, these acids and toxins can be broken down by fermentation into safe molecules. There is some evidence that suggests fermentation breaks down pesticides as well, but I do prefer, advocate and support organic food production.

Additional Nutrients: Fermented foods have more B vitamins than their raw counterparts. Micronutrients and metabolic byproducts also have special and unique benefits. For example, fermented vegetables contain isothyocyanates that are anti-carcinogenic, preventing cellular mutation.

Bacteria: Bacteria are the building blocks of life. Healthy human bodies have about 1 trillion bacteria, which are not parasites or free-loaders, but essential to our survival. They enable us to effectively function in our digestive system by synthesizing nutrients, withstanding bad bacteria and viruses, producing serotonin (in our brain) that is regulated by bacteria in our intestines and responsible for improving mental health. Research now suggests cells in our liver are actually regulated by bacteria in our intestines. Antibacterial products and foods and medicines diminish our biodiversity.

Fermentation Origins: The Question of Starters

The MOHK discovery box with almost a dozen varieties of fermented foods

We always have the question of origins: starter cultures predate recorded history. All starter cultures were originally #wildfermentation. People developed a technique to perpetuate development of fermented foods using the practice of “backslopping.” This can be found in lineages of yoghurt, for example. Now, you can buy the curated culture for a specific food, as an alternative. The third style of starter evolved into distinctive physical forms called SCOBYS (symbiotic communities of bacteria and yeast) such as the Mother of kombucha or milk kefir grains comes from the Caucus Mountains in Central Asia. Water kefir (tibicos from Mexico) or Japanese water crystals, Tibetan water crystal, California was called Bees Knees is another type of SCOBY.

Two Methods of Fermentation: Dry salt or wet brine

For dry salting.: Chop vegetables in pieces for more surface area. Pulling juice out of the vegetables themselves by squeezing and bruising the food. You need a certain minimum amount of surface area. Squeeze until juice comes out like a sponge. Then you know vegetables will be submerged. However, it is also possible to ferment vegetables whole or in large chunks. If you don’t have enough liquid by squeezing with your hands, then you just add a bit of water – typically a saltwater solution called a brine. I love the more concentrated flavour of the dry salt method because you are not adding more water.” Salt is its own type of preservative. Remember, it is always easier to add salt then subtract it. However, a rough guideline for new fermenters is 1.5% of weight – but salting is going to vary. My advice is salt to taste. There is no magic number. If you over salt , you can do two things. Firstly, add more vegetables or cover the vegetables with a bit of de-chlorinated water and let the water sit on vegetables for a few minutes. Pour off the excess water (but keep in mind that nutrients will pour out, too).